A digital cluster system in a Code Division Multiple Access (CDMA) standard has already possessed the good security and confidentiality, but for industry users who have higher requirements on the confidentiality, such as security departments including army, government departments and so on, it is more expected to use encrypted digital clustering, and the involved services include: common voices, one-to-one single call, one-to-many group call, short messages and data services and so on. An encrypted digital cluster system based on the CDMA standard is one end-to-end communication system, and compared to a non-encrypted common communication system, the main difference is that an encryption module is attached to an encryption terminal, so as to support the function for encrypting and decrypting different services. However, the synchronization of working states between the encryption terminal and the encryption module cannot be well implemented in the related art.